Arterial diameter ratio as a reliable predictor for upper limb steal syndrome in patients with arteriovenous fistula for hemodialysis

Objectives: The aim of this study is to assess the association between the anastomosis diameter enlargement and steal syndrome incidence in patients with upper limb arteriovenous fistula using ratios as reliable predictors. Material and Methods: An analytical cross-sectional prospective study was conducted. A total of 49 patients with AVF hemodialysis access were recruited. Twenty-four participants with positive steal syndrome and 25 control were enrolled in the study. Anastomosis diameter, anastomosis diameter ratio, and volume flow ratio were measured ultrasonographically by two expert vascular sonographers. These clinical parameters were recorded and analyzed to assess the difference and association. Patient risk factors and steal syndrome association were emphasized. Results: The study analysis indicates a strong association in the anastomosis diameter and anastomosis diameter ratio between steal and non-steal patients with a p-value ≤0.05. Additionally, there was a significant increase in the volume flow ratio in the patients with steal syndrome compared to the control group (p-value ≤0.05). There was a strong relationship between steal syndrome and the presence of peripheral arterial disease (73.9%, p = 0.001). The ICC index of absolute agreement between the two observers was ICC= 0.99 (95% CI 0.99–0.99, n = 10), indicating excellent agreement between observers. Conclusion: Anastomosis diameter and volume flow ratio strongly suggest that steal syndrome is associated with the increased diameter of anastomosis. Patients with a≥1.05 anastomosis diameter ratio have a greater risk of developing steal syndrome than those with an anastomosis ratio of ≤0.8. In addition, patients with a volume flow ratio ≥0.98 have an increased risk of developing steal syndrome than those with a volume flow ratio of ≤0.75.